fract-ol

This project is about creating graphically beautiful fractals.

First Steps

1.- Download libraries to fract-ol/src directory

minilibx-linux.tgz

minilibx_mms_beta.tgz

minilibx_opengl.tgz

2.- Unzip them with gunzip filename.tgz and extract files with tar --extract -f filename.tar

3.- Navigate to man folder of minilibx-linux. use pwdto know where you are and add it to ~/.manpath

MANDATORY_MANPATH /home/luis/Documentos/c/cursus/circle3/fract-ol/src/minilibx-linux/man

4.- Test man mlx, man mlx_loop, man mlx_new_image, man mlx_new_window y man mlx_pixel_put

5.- Watch two introductory videos in the 42 intra net e-learnig section.

Introduction to MinilibX

MinilibX : Events

6.- Create libmlx.a library ./configure' from minilibx-linux. make -F Makefile.gen show` shows flags required for compiling in your environment.

7.- Play with the 3 windows test/mlx-test the configuration process has created and study main.c that created them.

8.- Identify key codes for future iteraction wiht images. Do it in 42 and in your home. I separated codes in two files keys_mac.h and keys_ubuntu.h

9.- Hooks setting differs from Mac to linux in event masks. Be aware of such circunstance.

For mac :

	mlx_hook(w.win_ptr, ON_KEYDOWN, 0, &win_h_key_down, &w);

For linux:

	mlx_hook(w.win_ptr, ON_KEYDOWN, (1L << 0), &win_h_key_down, &w);

https://www.youtube.com/watch?v=FFftmWSzgmk

The complex numbers

I create a basic complex library to help me to simplify fractal formulas : create, add, multiply, absolutize (for the ship fractal) print ....

typedef struct s_complex
{
	float	x;
	float	y;
}	t_complex;

Three reference axis

I have to deal with 3 reference axis. The windows axis, the image axis, and the complex (real / imaginary axis)

This image helps us to get an idea about the window size required for this fractal. It will have a ratio aspect of 3:2 (600:400 || 900:600).

We need to shift de (0,0) origin from our window [(0,0), (600, 400)], situated in the left upper corner, to (400,200) or (600, 300). Then our image will become [(-400, 200), (200, -200)]

Additionally, a translation of pixel coordinates of the new window, [(-400, 200), (200, -200)] into fractal area [(-2, i), (1, -i)]

win (0,0)

      x-------------------------------------------------------------------x
  |          ^                                                        |
  |          |                                                        |
  |          |                                                        |
  |          |                                                        |
  |        offsety                                                    |
  |          |                                                        |
  |          |   x(15, 7)                                             |
  |          |                                                        |
  |          v img(0,0)                                               |
  |<-offsetx>#........................................................|..................#
  |          .                                                        |                  .
  |          .                                                        |                  .
  |          .                                                        |                  .
  |          .                                                        |                  .
  |          .                                                        |                  .
  |          .                                                        |                  .
  |          .                                                        |                  .
  |          .               # (15,7)                                 |                  .
  x-------------------------------------------------------------------xwin (600, 400)    .
             .                                                                           .
             .                                                                           .
             .                                                                           .
             .                                                                           .
	     #...........................................................................#

At zero zoom the relationship between win and img is 1:1

img2win transformation ==> x = # - offsets

win2img transformation ==> # = x + offsets

To support this three references i defined one struct for the image,

typedef struct s_img
{
	void		*img_ptr;
	char		*addr;
	int		bits_per_pixel;
	int		line_length;
	int		endian;
	t_point		size;
	t_point		lu;
	t_point		rd;
	int		x_0;
	int		y_0;
	float		real;
	float		imag;
	float		r_x;
	float		r_y;
	t_complex	z;
}	t_img;

and other for the window

typedef struct s_win
{
	void		*mlx_ptr;
	void		*win_ptr;
	t_img		img;
	char		*title;
	t_point		size;
	t_point		lu;
	t_point		rd;
	t_point		md;
	t_point		mu;
	t_point		mm;
	int			zoom;
	float		scale;
	t_point		shift;
	int			palette;
	int			iteractions;
}				t_win;

The fractal concept

It is a iterative calculation that uses the previous result of the same calculation

Conjunto Mandelbrot	Conjunto Julia de parametro c
z0 = 0	z0 = z
z1 = F(z0) = z0^2 + c	z1 = F(z0) = z0^2 + c
z2 = F(z1) = z1^2 + c	z2 = F(z1) = z1^2 + c
...
...
zn+1 = F(zn) = zn^2 + c	zn+1 = F(zn) = zn^2 + c

The higher the n, the higher resolution the fractal will have and the higher workload for yor computer. The function loops thru n till MAX iterations or when the module of the Z complex is > 4.

If mod(z) does not growth .....

c belongs to Mandelbrot set.

Initial z belongs to Juia set of parameter c.

In this case c (when Mandelbrot) or Z when (Julia) get BLACK color. Otherwise C or Z get a color from a palette. Ths color with the index of the nth iterations that made mod(z) > 4.

This image shows range of real an imaginary axis in the complex numbers world.

Mandelbrot

zoom=55 n=55

zoom=80 n=100

Julia

Ship

What i read/watch

Monitor aspect ratio, dpi, resolution

zooming & Panning

one minilibx tutorial

other tutorial

otheer minilibx tutorial

What i learnt.

In this proyect i started to used sanitize flag at compilation time. That helps me to find memory leaks and segmentation fault.

I added man pages to man path.

i discover vim -p *.c to open all files in the folder one shot.

There are differences betwenn keycodes in differente OS.